Process of treating rock asphalt for shipment and laying



:Patented. Apr. 12, 1927.

UNITED STTATESIPATENT OFFICE;

JOHN w; rnnz'mn, or SAN. an'romo, TEXAS, AssIeNoa TO ovarian Rocx mm:

- commu es salt ANTONIO, TEXAS raocnss or TREATING ROCK ASPHALT Fort SHIPMENT Ami LAYING.

- No Drawing My .invention relates to a' new and iin-. proved processfor the preparation and'sh1pm'ent of limestone rock asphalt, for use in surfacing roads, streets, floors, etc.

5 Limestone rock asphalt or rock asphalt. occurs in nature and is found in scattered de posits indifferent parts of the world. It

I .comprisesa pure limestone base of a porous,

fossiliferous character, mostly shell, more or less thoroughly and intimately impregnated with asphalt. The asphalt in thisrocki-s approximately pure and, due to the porous character .of the limestone, the lighter distillates of the bitumen have passed off .in the ages since its formation, leaving a hard bitu-- men. The said rock asphalt, as-itis found in'the United States, is'par'ticularly adapted to Withstand Wear of trafiioand weather con- .ditions when properly prepared and -in-' stalled-inpI-ace. i

Inconsideration of my invention, it. must be recognized that limestone rockasphalt is a natural product and differs widely: in

r physical analysis from an artificial asphalt I 2 paving material or a sandstone rock asphalt,

which 'haveapproximately the same chem.

ical analysis. This. difference between the limestone rock asphalt and the artificial paving material or the sandstone rock asphalt is 0 clearly indicated in the fact that the'asphalt is. contained within each particle in the former material, and is a coating on theoutside of each particle in the two latter mate tion in whichrit' may be readily removed rials. v. In the construction of asphalt pavements or surfacing, it has been found advisable to so govern thepenetration of the asphaltic content-by means of fiuxing or hardening agents, that the finished product falls within 40 certain specified limits calculated-to enable the material to provide satisfactory service i within the range of the temperature ex-' 55, has been the custom to ship the 1ime stone ,added, and heat applied in case the material erating the necessary plant oftentimes premines.

with limestone. rock Application filed August- 29," 1924. semi No. 735,021

rock asphalt to the plantwhere it is to be prepared, in the form of rubble, spall or one man rocki.

This has been found necessar for the reason that the material, if shippe from the rock asphalt mines-in a finely pulverized state, would amalgamataand adhere into one mass, making the handling of the same very difficult and necessi'tating. that it be re-- pulverized at the: point of use. After arrival at the plant, .the rock asphalt is usually run through a pulverized and then into suitable mixing machines where the flux oil is is to be laid hot.- This method requires that the plant used in preparation of the materialbe-transported to and from each job; also workmen skilled in the operation of the plant must be transported to the location and maintained during the period of the work. 7 It is further necessary to provide power, Wa-

ter and storage space for each set-up, all of which adds fixed and contingent expense.

'Thecost of transporting, setting-up and 0p eludes the use of this type of material for certain work, particularly the smaller jobs.

' f Itis an object of my invention to provide a process by means of which the limestone rock asphalt may be preparedy'at the mines where it is produced, or at any other suitable location, in a manner that will permit of'shipm ent'to distant points and in a condifromthecars and be ready to lay, thus elimi- 9 nating the necesssity of an individual, plant for each job.

To accomplish this purpose, I use inaddition to the limestone rock asphalt, an asphaltic' base oil or other fiuxing agent, naptha, and a peculiar, porous limestone found .in the locality oi the rock asphalt In preparing the 'material, a mixing machine of ordinary construction is employed and I first introduce into the mixer approximately 25% of the porous limestone, which has been previously pulverized to the de-, sired degree of fineness. This percentage pi. limes'ztonemay be increased or decrease'dlas; 1. desired, and is governed to a greateagtent by the percentage of bitumen in -heli:eek

asphalt to be used.- Next, I intro uee the naptha or other suitable solventi anamount of approximately two to-ft'i gallens to each ton of finished material and cause this to be thoroughly mixed with the limestone dust. The napthais rapidly absorbed by the limestone in the same manner that a sponge absorbs Water. The amount of naptha to be used may be varied as desired depending on the length of time the material is to be kept before laying. Next, I

introducethefasphaltie oil or other flexing agent into the mixture in sufiicient quantity to provide the desired penetration in the finished product, generally about three to six gallons for each ton of finished material. Finally, I introduce the rock asphalt which has been previously pulverized to the proper i'ineness and cause the entire charge to be thoroughly mixed. By using this sequence,

It find I obtain a perfect miaiture of themgredients in the shortest time, because the action of the naptha which has been introdueed into the limestone partly dissolves the flux oil and assists in uniform distribution. Then also, it is found that the assimilation of both the naptha and the flux oil is more perfect in thelimestone than it is in the rock asphalt, and that, when the pulverized rock asphalt 'is finally intro slowly evaporating, throws oilup or duced, there are no accumulations, pockets or balls of theheavy fluxing oil to be broken up. Howevelyl do not confine myself to the exact procedure or sequence described but may change at will one or more of the ingredients aud the percentage used. As an illustration, it'might prove advisable at certain times to usesand instead of the porous limestone,or to eliminate the limestone or sand entirely, as in the ease of exceptionally lean rock asphalt.

The material thus prepared may he trans the ten of the charge.

aeeawe "When thus prepared and transported to the place Where it isto' housed, the material may be readily removed from the cars and hauled to the job, Where it may be raked, levelled and rolled .on the prepared base, which mayor may not be previously treated-with oil. Where desired the material maybe heated before placing and roll- 'ing, but this not necessary to secure good results.

- Having thus described my invention, what I claim as ne'wancl desireto protect by Letters Patent is:

1. A process of preparinglimestone rock asphalt in condition for shipment ready to lay, comprising first, crushing and pulverizing a quantity of porousflimestone, then mixing with said limestone a small quantity of solvent; then introducing a small proportion of fluxing agent, finely crushing limestone rock asphalt and mixing it with the prepared limestone in the proportion of about four parts of the rock asphalt to one of the prepared limestone dust.

for shipment ready tolay, comprising finely eras-lung the rock asphalt, and mixing there 2. A process of preparing rock asphaltwith about one-fourth of its bulk in porous limestone dust treated by first mixingtherewith a solvent and'then asmall proportion of fiuxing agent in the proportion of approximately three to six gallons of flux to The process (if preparing rock asphalt for shipment ready to lay, ineludingpul- I verizmg the rock asphalt andmixing therewith a substantial proportion of porous limestone dust prepared by mixing therewith a volatile solvent, and a small quantity of asphaltic oil. I

'lhe process of preparing limestone rock asphalt for shipment ready to lay, comprising pulverizing the rock asphalt and mixing therewith approximately 25% of its bullr in porous limestone dust prepared by mixing therewith approximately three gallons o'l' solvent-to the ton of the total charge, and five gallons of asphalt-i0 flux to the ton finished material.

In testimony whereof I hereunto aiiix my signature this 26th day of August, A. D.

Joint W. rename. 

